Projectile provided with a safety device



Nov. 28, 1961 E. w. BRANDT PROJECTILE PROVIDED WITH A SAFETY DEVICE Filed March 25, 1960 3,ld,397 Patented Nov. 28, 1961 ice 3,010,397 PROIECTILE PROVIDED WITH A SAFETY DEVICE Edgar William Brandt, Geneva, Switzerland, assignor to Anstalt fiir die Entwicklung von Erfindungen r nd gewerhlichen Anwendungen ENERGA, a corporation of Vaduz, Liechtenstein Filed Mar. 25, 1960, Ser. No. 17,586 Claims priority, application Switzerland Apr. 20, 1959 3 Claims. (Cl. 10256) This invention relates to projectiles and is concerned with means for ensuring the safety of projectiles, especially hollow charge projectiles, when being transported or manipulated or, when fired, for a certain distance beyond the mouth of the weapon.

The invention is concerned with projectiles of the type comprising a fuse at the head of a body enclosing the explosive, offensive charge, a safety device at the rear of said body, which device has a safety chamber in which is housed a detonator held in the inactive position outside the charge, and means adapted to release the said detonator after the departure of the shot in order to permit the same to take an active position in the explosive charge.

According to the invention a projectile of the type set forth is characterised in that the safety device in addition comprises, between the detonator, when in its inactive position, and the internal wall of said chamber, an assembly of projecting peripheral damping elements which constitute a cushion which is deformable and collapsible against the wall of the safety chamber under the action of the force of the detonator, in the event of its inadvertent explosion in the position outside the charge, without there being any rupture of said wall.

It has previously been proposed, see Patent No. 2,737,- 888, to house inside the safety chamber of a projectile 11 intermediate wall capable of mitigating the explosive action of the detonator. This precaution may prove inadequate, particularly when the specifications of construction require a minimum weight and size of the safety chamber for a detonator the relatively powerful explosive force of which is demanded for the effect-for example armour-piercing, or anti-personnelwhich the projectile is required to produce on the target.

In accordance with the invention, the assembly of damping elements interposed between the detonator and the wall of the safety chamber in part absorbs, by deformation and collapse, the force of the detonator, should the latter explode inadvertently in the out-of-charge position. In this way, rupture of the wall of said chamber is prevented and consequently the production of splinters which would endanger attendant personnel is avoided.

In one particular form of construction, the assembly of damping elements is constituted by circular fins contiguous with the external wall of an intermediate chamber in which the detonator is housed. Should the detonator be actuated by accident in the inactive position, the rupture of the intermediate chamber brings the fins into contact with the internal wall of the safety chamber. Due to the effect of the resulting gas pressure the fins are deformed and collapse against the wall without damaging the same.

The fins carried by the intermediate chamber are preferably constituted of a ductile and therefore easily deformable metal (for example aluminium or an aluminium alloy) so as to bring about the utmost damping effect.

The thickness of the fins preferably decreases from the axis towards the periphery of the safety chamber, so as to enhance the damping effect of said fins.

In order to enable the invention to be more readily understood, reference will now be made to the accompanying drawings, which illustrate diagrammatically and by way of example one embodiment thereof, and in which FIGURE 1 is a view, partly in section, of a hollow projectile,

FIGURE 2 is an axial section, on a larger scale, of a detail of FIGURE 1, and

FIG. 3 is a fragmentary side elevation of the detonator release device.

The projectile shown in the drawings comprises a fuse 1, a body 2, a tail 3 and fins 4. The tail 3 constitutes a chamber in which is housed a self-propelling charge.

A safety device is interposed between the body 2 and the tail 3 and comprises a chamber 5, a detonator 6 arranged within a detonator carrier 7, which is in turn disposed in an intermediate chamber 8 which is surrounded by a base member 8a. The external wall of said base member is provided with fins 9 of a ductile and easily deformable metal (such as aluminium or aluminium alloy). The fins 9, contiguous with the wall of the chamber 3, are circular and superposed upon one another along planes perpendicular to the axis of the projectile. They are of decreasing thickness from the axis towards the periphery, as shown in FIGURE 2, and a peripheral space is arranged between the fins 9 and the internal wall of the chamber 5.

A pin 10 passes through the wall of the chamber 8 and engages in a groove 11 formed in the detonator carrier 7, the pin 10 retaining the detonator carrier 7 in a position of safety outside the charge, against the spring 12. The shape of the groove 11 is shown in FIG. 3, which is a development of the groove in a plane. Such a safety arrangement is disclosed in United States Patent No. 2,595,757.

The explosive, constituted by two superposed charges 13 and 14, surrounds a channel 15 which is occupied in the armed position by the detonator carrier 7 and detonator 6 after unlocking of the safety members constituted by the pin It} and the slot 11.

On the departure of the shot and through positive acceleration, the detonator carrier 7 moves back against the spring 12 and the pin 10 passes through the rising portion of the slot 11. Then, due to the deceleration resulting from air resistance, the detonator carrier is displaced towards the front, the pin 10 passing through the descending portion of the slot 11. When the detonator carrier 7 is in place in a tubular element 15 lining the channel 15, the detonator 6 is in the active position, ready to function.

In the safety position (FIGURE 2), inadvertent functioning of the detonator 6, which is unable to prime the explosive 13 and 14, causes the progressive deformation and crushing of the fins 9, which come to bear against the internal wall of the chamber 5. The fins 9, taking the place of a damping cushion, absorb part of the kinetic energy of the explosion of the detonator 6 and prevent rupture of the wall of the chamber 5. In this way, rupture of said wall and the emission of hot gases under pressure are prevented, which might, in the absence of the aforesaid arrangements, set fire to other projectiles during transport or in storage. At the same time the risk of any accident on the departure of the shot, resulting from fragmentation of the projectile in two parts is suppressed.

I claim:

1. A projectile comprising a hollow body, a fuse in the nose of the projectile, a shaped explosive charge inside the hollow body and having an axial channel for transmitting fire from the fuse, a safety chamber at the O rear of said charge, a base member located in said safety chamber at the rear part of said channel, a housing in said base member, a detonator, means for holding said detonator in a retracted inactive position in said housing rearwardly of said charge and means for releasing said detonator permitting it to move forwardly into the channel to receive fire from the fuse, said base member comprising, between the detonator and the internal wall of said safety chamber, a plurality of projecting metallic peripheral damping elements integral with said base member and constituting a cushion deformable and collapsible against the Wall of the safety chamber in the event of inadvertent explosion of said detonator in its retracted inactive position, to avoid rupture of said wall.

2. -A projectile comprising a hollow body, a fuse in the nose of the projectile, a shaped explosive charge inside the hollow body and having an axial channel for transmitting fire from the fuse, a safety chamber at the rear of said charge, a base member located in said safety chamber at the rear part of said channel, a housing in detonator permittingit to move forwardly into the channel to receive fire from the fuse, said base member corn- 7 prising, between the detonator and the internal wall of said safety chamber, 'a plurality of circular metallic fins integral with theexternal wall of said base member, said assemblyconstituting a cushion deformable and collapsible against the Wall of the safety chamber in the event of inadvertent explosion of said detonator in its retracted inactiveposition, to avoid rupture of said wall.

3. A projectile according to claim 2 in which the said fins are of decreasing'thickness from the axis towards the periphery of said base.

I References Cited in the'file of this patent UNITED STATES PATENTS Shaifner Dec. 18, 1866 Brandt Mar. 13, 1956 

